Help diagnosing plant problem *pics

27 days old from seed, the tips are brownish yellowish with small black dots, im thinking potassium, could anyone help me identify this?

u need to give specifics bout your set-up man. (PH,water times,feed sched,and what nutes,PPM?)

PH 6.2 to 7.1, i buffer it every day or two as it slowly rises. I use a waterfarm with a hybrid drip/ebb and flow using flora nova bloom and calmg and distilled water with a touch of tap water ppm is 550

I also have a journal with more info in my grow thread

I have the same issue around the edges .Using GH flora, bloom and Micro too/ with b52 and some cal mag. I'm in 5 gal dwc . Other than this issue they look fine and bushy.Some helpers say cal and some say phosphate. But I'm not in soil and using GH 's feeding chart why would I be lacking anything..ph is 5.7 -6.0 and ppm is around 750???? any advice is welcome

bah i know i don't know if its nute burn or deficient Potassium or what but im trying higher nutes right now. I don't think it'd be Cal/mg for me as i have atleast 50 ppms from it coming from the cal/mg alone, plus the nova bloom